Measurement of ${\chi }_{cJ}$ decaying into $p\bar{n}{\pi }^{-}$ and $p\bar{n}{\pi }^{-}{\pi }^0$

Using a data sample of $1.06\times {10}^8$ $\text{psip}$ events collected with the BESIII detector in 2009, the branching fractions of $\chi_{cJ}\to p\bar{n}\pi^{-}$and$\chi_{cJ}\to p\bar{n}\pi^{-}\pi^{0}$($J$=0,1,2) are measured{Throughout the text, inclusion of charge conjugate modes is implied if not stated otherwise.}. The results for ${\chi }_{c0}\to p\bar{n}{\pi }^{-}$ and ${\chi }_{c2}\to p\bar{n}{\pi }^{-}$ are consistent with, but much more precise than those of previous measurements. The decays of ${\chi }_{c1}\to p\bar{n}{\pi }^{-}$ and ${\chi }_{cJ}\to p\bar{n}{\pi }^{-}{\pi }^0$ are observed for the first time.